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Potential Targets (potential + target)
Kinds of Potential Targets Selected AbstractsEffects of postnatal ethanol exposure on neurotrophic factors and signal transduction pathways in rat brainJOURNAL OF APPLIED TOXICOLOGY, Issue 3 2008Vittorio Fattori Abstract Exposure to ethanol during development induces severe brain damage, resulting in a number of CNS dysfunctions including microencephaly and mental retardation. Potential targets of ethanol-induced neurotoxicity include neurotrophic factors and their signal transduction pathways. In the present study, rat pups were given ethanol at the dose of 5 g kg,1 via gavage from postnatal day (PND) 5 to 8, and mRNA expression of nerve growth-factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophic factor-3 (NT-3) in the cerebral cortex was examined, with attention to signal transduction, on PND 8. The mRNA level of BDNF was decreased by ethanol while those of NGF or NT-3 were not changed. Brain weights were decreased and the levels of phospho-MAPK, phospho-p70S6K and phospho Akt were decreased while phosphor-PKC, and phospho-CREB remained unchanged. These results suggest that BDNF and its related signal pathways involving Akt, MAPK and p70S6K are potential targets of ethanol-induced developmental neurotoxicity. Copyright © 2007 John Wiley & Sons, Ltd. [source] Tumour necrosis factor-like weak inducer of apoptosis (TWEAK) and its receptor Fn14 during cardiac remodelling in ratsACTA PHYSIOLOGICA, Issue 1 2010E. Mustonen Abstract Aim:, Accumulating evidence supports the concept that proinflammatory cytokines play an essential role in the failing heart. We examined the concomitant tumour necrosis factor-like weak inducer of apoptosis (TWEAK)/Fn14 expression in myocytes in vitro as well as in vivo in cardiac remodelling. Methods:, We assessed TWEAK and its receptor Fn14 expression in response to angiotensin (Ang) II, myocardial infarction (MI) as well as to local adenovirus-mediated p38 gene transfer in vivo. The effect of various hypertrophic factors and mechanical stretch was studied in neonatal rat ventricular myocyte cell culture. Results:, Ang II increased Fn14 levels from 6 h to 2 weeks, the greatest increase in mRNA levels being observed at 6 h (6.3-fold, P < 0.001) and protein levels at 12 h (4.9-fold, P < 0.01). TWEAK mRNA and protein levels remained almost unchanged during Ang II infusion. Likewise, a rapid and sustained elevation of Fn14 mRNA and protein levels in the left ventricle was observed after experimental MI. Moreover, local p38 gene transfer increased Fn14 mRNA and protein but not TWEAK levels. Fn14 immunoreactive cells were mainly proliferating non-myocytes in the inflammation area while TWEAK immunoreactivity localized to cardiomyocytes and endothelial cells of the coronary arteries. Hypertrophic agonists and lipopolysaccharide increased Fn14 but not TWEAK gene expression in neonatal rat myocytes, while mechanical stretch upregulated Fn14 and downregulated TWEAK gene expression. Conclusions:, In conclusion, the cardiac TWEAK/Fn14 pathway is modified in response to myocardial injury, inflammation and pressure overload. Furthermore, our findings underscore the importance of Fn14 as a mediator of TWEAK/Fn14 signalling in the heart and a potential target for therapeutic interventions. [source] Multicenter, randomized, double-blind, active comparator and placebo-controlled trial of a corticotropin-releasing factor receptor-1 antagonist in generalized anxiety disorder,DEPRESSION AND ANXIETY, Issue 5 2010Vladimir Coric M.D. Abstract Background: Antagonism of corticotropin-releasing factor (CRF) receptors has been hypothesized as a potential target for the development of novel anxiolytics. This study was designed to determine the safety and efficacy of pexacerfont, a selective CRF-1 receptor antagonist, in the treatment of generalized anxiety disorder (GAD). Method: This was a multicenter, randomized, double-blind, placebo-controlled and active comparator trial. Two hundred and sixty patients were randomly assigned to pexacerfont 100,mg/day (after a 1 week loading dose of 300,mg/day), placebo or escitalopram 20,mg/day in a 2:2:1 ratio. The primary outcome was the mean change from baseline to end point (week 8) in the Hamilton Anxiety Scale total score. Results: Pexacerfont 100,mg/day did not separate from placebo on the primary outcome measure. The half-powered active comparator arm, escitalopram 20,mg/day, demonstrated efficacy with significant separation from placebo at weeks 1, 2, 3, 6, and 8 (P<.02). Response rates for pexacerfont, placebo, and escitalopram were 42, 42, and 53%, respectively. Genetic and psychometric rating scale data was obtained in 175 randomized subjects. There was a significant association between a single nucleotide polymorphism (SNP) of the gene encoding plexin A2 (PLXNA2-2016) with the HAM-A psychic subscale score for the entire cohort at baseline (FDR-adjusted P=.015). Conclusions: Pexacerfont did not demonstrate efficacy compared to placebo for the treatment of GAD. Whether these findings are generalizable to this class of agents remains to be determined. Our preliminary genetic finding of an association between a SNP for the gene encoding plexin A2 and an anxiety phenotype in this study merits further exploration. The trial was registered at clinicaltrials.gov (NCT00481325) before enrollment. Depression and Anxiety, 2010. © 2010 Wiley-Liss, Inc. [source] The role of renin,angiotensin,aldosterone system-based therapy in diabetes prevention and cardiovascular and renal protectionDIABETES OBESITY & METABOLISM, Issue 12 2008Hussam Abuissa Hypertension increases the risk of type 2 diabetes mellitus (T2DM) and cardiovascular disease. In addition to lowering blood pressure, blockade of the renin,angiotensin,aldosterone system (RAAS) reduces the risk of new-onset T2DM and offers renal protection. Using a MEDLINE search, we identified multiple trials that reported the incidence of T2DM in patients taking inhibitors of RAAS. In this review, we will discuss the RAAS as a potential target in diabetes prevention and the mechanisms through which inhibitors of this system achieve such an important effect. We will also shed light on the beneficial cardiovascular and renal effects of RAAS blockade. Although multiple studies have demonstrated that inhibitors of RAAS, especially angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, can reduce the incidence of T2DM, randomized controlled studies are still needed to further elucidate their exact role in diabetes prevention. [source] Monogenic migraine syndromes highlight novel drug targetsDRUG DEVELOPMENT RESEARCH, Issue 7 2007J. Jay Gargus Abstract In the post-genomic era, the paradigm for drug discovery has changed, as every gene may become a potential target. Genetic diseases provide a special window into gene target selection. This approach is being applied to migraine making use of the genes and mutations causing familial hemiplegic migraine (FHM). FHM is caused by missense mutations in CACNA1A, altering a neuronal P/Q Ca2+ channel, in ATP1A2, altering ,2 Na,K-ATPase, and in SCN1A, altering a neuronal sodium channel. These genes provide insights into migraine pathogenesis that likely extend to other forms of migraine as well. Since the three FHM genes are only co-expressed in neurons, FHM is a neuronal, not a vascular, disease and because they all encode ion transport proteins, FHM is a neuronal channelopathy,meaning meta-stable neuronal hyperexcitability is the substrate of migraine, much as it is for genetic epilepsy syndromes. This similarity is reinforced, since different mutations of all three FHM genes can produce seizure syndromes. This has implications for drug discovery in that seizure medications already known to modulate the FHM channel mechanisms warrant more targeted development, and that drugs targeted to vascular headaches, such as the historically effective triptans, or experimental botulinum toxin, may well work by similar nonvascular mechanisms. Finally, in model neurogenetic systems such as Caenorhabditis elegans, the FHM genes also provide both a comprehensive means to discover all genes involved in their signaling pathway,genes potentially involved in common forms of the disease, and an in vivo whole animal means to screen rapidly for novel therapeutics. Drug Dev Res 68:432,440, 2007. © 2008 Wiley-Liss, Inc. [source] Suppression of inflammatory responses by celastrol, a quinone methide triterpenoid isolated from Celastrus regeliiEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 9 2009D. H. Kim Abstract Background, Celastrol, a quinone methide triterpenoid isolated from the Celastraceae family, exhibits various biological properties, including chemopreventive, antioxidant and neuroprotective effects. In this study, we showed that celastrol inhibits inflammatory reactions in macrophages and protects mice from skin inflammation. Materials and methods, Anti-inflammatory effects of celastrol (0,1 ,M) were examined in lipopolysaccharide (LPS)-stimulated RAW 264·7 macrophages. To investigate the effects of celastrol (0,50 ,g per mice) in vivo, activation of myeloperoxidase (MPO) and histological assessment were examined in the 12- O -tetradecanoyl-phorbol-13-acetate (TPA)-induced mouse ear oedema model. Results, Our in vitro experiments showed that celastrol suppressed not only LPS-stimulated generation of nitric oxide and prostaglandin E2, but also expression of inducible nitric oxide synthase and cyclooxygenase-2 in RAW264·7 cells. Similarly, celastrol inhibited LPS-induced production of inflammatory cytokines, including tumour necrosis factor-, and interleukin-6. In an animal model, celastrol protected mice from TPA-induced ear oedema, possibly by inhibiting MPO activity and production of inflammatory cytokines. Conclusions, Our data suggest that celastrol inhibits the production of inflammatory mediators and is a potential target for the treatment of various inflammatory diseases. [source] Natural killer cells become tolerogenic after interaction with apoptotic cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 6 2010Wai Po Chong Abstract NK cells are effectors in innate immunity and also participate in immunoregulation through the release of TGF-,1 and lysis of activated/autoreactive T cells. Apoptotic cells (AC) have been shown to induce tolerogenic properties in innate immune cells, including macrophages and dendritic cells, but not NK cells. In this study, we demonstrated that after interaction with AC, NK cells released TGF-,1, which in turn suppressed the production of IFN-, by NK cells upon IL-12 and IgG activation. We further identified phosphatidylserine as a potential target on AC for the NK cells, as phosphatidylserine could stimulate NK cells to release TGF-,1, which in turn suppressed CD4+ T-cell proliferation and activation. Moreover, AC-treated NK cells displayed cytotoxicity against autologous-activated CD4+ T cells by upregulating NKp46. This lysis occurred in part through the NKp46-vimentin pathway, as activated CD4+ T cells expressed vimentin on the cell surface and blocking of vimentin or NKp46, but not other NK-cell receptors, significantly suppressed the NK-cell cytotoxicity. We report here a novel interaction between NK cells and AC, resulting in the tolerogenic properties of NK cells required for immune contraction. [source] Glucocorticoid-induced TNFR family-related protein (GITR) activation exacerbates murine asthma and collagen-induced arthritisEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 12 2005Manish Patel Abstract Glucocorticoid-induced TNFR family-related protein (GITR) is expressed at low levels on resting T cells, B cells and macrophages but at high levels on regulatory T cells (Treg). Although GITR expression is up-regulated on CD4+ effector cells upon activation, the role of GITR in Th1 and Th2 cell development is unclear. We report here that activation of GITR signalling by anti-GITR antibody markedly enhanced the induction of both Th1 and Th2 cytokine production by naive CD4+CD25, T cells. Consistent with this observation, anti-GITR antibody significantly enhanced the expression of the key Th1 (T-bet) and Th2 (GATA3) transcription factors in vitro. Administration of anti-GITR mAb in a murine model of arthritis significantly exacerbated the severity and onset of joint inflammation with elevated production of TNF-,, IFN-,, IL-5, and collagen-specific IgG1. Administration of anti-GITR mAb also significantly exacerbated murine allergic airways inflammation with elevated production of OVA-specific IFN-,, IL-2, IL-4, IL-5, and IgE. Finally, we demonstrated that adoptive transfer of CD4+GITR+ T cells effectively abolished airway inflammation induced in SCID mice reconstituted with CD4+GITR, T cells. Our results therefore provide direct evidence that GITR can modulate both Th1- and Th2-mediated inflammatory diseases, and may be a potential target for therapeutic intervention. [source] Riluzole inhibits the persistent sodium current in mammalian CNS neuronsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2000Andrea Urbani Abstract The effects of 0.1,100 ,m riluzole, a neuroprotective agent with anticonvulsant properties, were studied on neurons from rat brain cortex. Patch-clamp whole-cell recordings in voltage-clamp mode were performed on thin slices to examine the effects of the drug on a noninactivating (persistent) Na+ current (INa,p). INa,p was selected because it enhances neuronal excitability near firing threshold, which makes it a potential target for anticonvulsant drugs. When added to the external solution, riluzole dose-dependently inhibited INa,p up to a complete blocking of the current (EC50 2 ,m), showing a significant effect at therapeutic drug concentrations. A comparative dose-effect study was carried out in the same cells for the other main known action of riluzole, the inhibitory effect on the fast transient sodium current. This effect was confirmed in our experiments, but we found that it was achieved at levels much higher than putative therapeutic concentrations. Only the effect on INa,p, and not that on fast sodium current, can account for the reduction in neuronal excitability observed in cortical neurons following riluzole treatment at therapeutic concentrations, and this might represent a novel mechanism accounting for the anticonvulsant and neuroprotective properties of riluzole. [source] Mycobacterium tuberculosis Thymidine Monophosphate Kinase Inhibitors: Biological Evaluation and Conformational Analysis of 2,- and 3,-Modified Thymidine AnaloguesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 15 2003Philippe Van Rompaey Abstract Mycobacterium tuberculosis thymidine monophosphate kinase (TMPKmt) has recently been introduced as a potential target for the structure-based design of anti-tuberculosis drugs. Based on the TMPKmt X-ray structure and previous S.A.R. studies, we synthesised the nucleoside analogues 3a,b, 6a,b, 7a,b, and 8a,b, modified in 2,- and 3,-position of the ribofuranose ring moiety. To our surprise, these analogues showed only moderate binding affinity (i.e. Ki between 118 and 1260 ,M). This prompted us to investigate the conformational features of these nucleosides. We concluded that compounds of this series, especially 8a,b, are strongly biased towards the "Northern" furanose ring conformation, whereas X-ray crystallography reveals a preference of TMPKmt for the opposite "Southern" conformers. This paper covers the synthesis, biological evaluation and conformational features (i.e. preferred ring puckering) of the 2,- and 3,-modified dT analogues. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Sustained activation of ERK1/2 by NGF induces microRNA-221 and 222 in PC12 cellsFEBS JOURNAL, Issue 12 2009Kazuya Terasawa MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression by inhibiting translation and/or inducing degradation of target mRNAs, and they play important roles in a wide variety of biological functions including cell differentiation, tumorigenesis, apoptosis and metabolism. However, there is a paucity of information concerning the regulatory mechanism of miRNA expression. Here we report identification of growth factor-regulated miRNAs using the PC12 cell line, an established model of neuronal growth and differentiation. We found that expression of miR-221 and miR-222 expression were induced by nerve growth factor (NGF) stimulation in PC12 cells, and that this induction was dependent on sustained activation of the extracellular signal-regulated kinase 1 and 2 (ERK1/2) pathway. Using a target prediction program, we also identified a pro-apototic factor, the BH3-only protein Bim, as a potential target of miR-221/222. Overexpression of miR-221 or miR-222 suppressed the activity of a luciferase reporter activity fused to the 3, UTR of Bim mRNA. Furthermore, overexpression of miR-221/222 decreased endogenous Bim mRNA expression. These results reveal that the ERK signal regulates miR-221/222 expression, and that these miRNAs might contribute to NGF-dependent cell survival in PC12 cells. [source] Thermodynamic characterization of substrate and inhibitor binding to Trypanosoma brucei 6-phosphogluconate dehydrogenaseFEBS JOURNAL, Issue 24 2007Katy Montin 6-Phosphogluconate dehydrogenase is a potential target for new drugs against African trypanosomiasis. Phosphorylated aldonic acids are strong inhibitors of 6-phosphogluconate dehydrogenase, and 4-phospho- d -erythronate (4PE) and 4-phospho- d -erythronohydroxamate are two of the strongest inhibitors of the Trypanosoma brucei enzyme. Binding of the substrate 6-phospho- d -gluconate (6PG), the inhibitors 5-phospho- d -ribonate (5PR) and 4PE, and the coenzymes NADP, NADPH and NADP analogue 3-amino-pyridine adenine dinucleotide phosphate to 6-phospho- d -gluconate dehydrogenase from T. brucei was studied using isothermal titration calorimetry. Binding of the substrate (Kd = 5 µm) and its analogues (Kd =1.3 µm and Kd = 2.8 µm for 5PR and 4PE, respectively) is entropy driven, whereas binding of the coenzymes is enthalpy driven. Oxidized coenzyme and its analogue, but not reduced coenzyme, display a half-site reactivity in the ternary complex with the substrate or inhibitors. Binding of 6PG and 5PR poorly affects the dissociation constant of the coenzymes, whereas binding of 4PE decreases the dissociation constant of the coenzymes by two orders of magnitude. In a similar manner, the Kd value of 4PE decreases by two orders of magnitude in the presence of the coenzymes. The results suggest that 5PR acts as a substrate analogue, whereas 4PE mimics the transition state of dehydrogenation. The stronger affinity of 4PE is interpreted on the basis of the mechanism of the enzyme, suggesting that the inhibitor forces the catalytic lysine 185 into the protonated state. [source] Fimbriae of uropathogenic Proteus mirabilisFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2007Sérgio P. D. Rocha Abstract Proteus mirabilis is a common causative agent of cystitis and pyelonephritis in patients with urinary catheters or structural abnormalities of the urinary tract. Several types of fimbriae, which are potentially involved in adhesion to the uroepithelium, can be expressed simultaneously by P. mirabilis: mannose-resistant/Proteus -like (MR/P) fimbriae, P. mirabilis fimbriae (PMF), uroepithelial cell adhesin (UCA), renamed by some authors nonagglutinating fimbriae (NAF), and ambient-temperature fimbriae (ATF). Proteus mirabilis is a common cause of biofilm formation on catheter material and MR/P fimbriae are involved in this process. The considerable serious pathology caused by P. mirabilis in the urinary tract warrants the development of a prophylactic vaccine, and several studies have pointed to MR/P fimbriae as a potential target for immunization. This article reviews P. mirabilis fimbriae with regard to their participation in uropathogenesis, biofilm formation and as vaccine targets. [source] Molecular mechanisms underlying inflammatory lung diseases in the elderly: Development of a novel therapeutic strategy for acute lung injury and pulmonary fibrosis,GERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 3 2005Takahide Nagase In the elderly, inflammatory lung diseases, including acute lung injury and pulmonary fibrosis, are significant in terms of both mortality and difficulty in management. Acute respiratory distress syndrome (ARDS) is an acute lung injury and the mortality rate for ARDS ranges from 40 to 70% despite intensive care. Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal disorder of the lung parenchyma. No useful drugs are currently available to treat IPF. However, molecular mechanisms underlying these lung diseases are little understood and the development of a novel therapeutic strategy is urgently needed. Platelet-activating factor (PAF) and metabolites of arachidonic acid, i.e. eicosanoids, are lipid mediators that have various biological effects. A key enzyme for the production of these inflammatory mediators, including eicosanoids and PAF, is phospholipase A2. In particular, cytosolic PLA2 (cPLA2) is especially important. The purpose of this article is to report novel findings regarding the role of PAF and cPLA2 in lung inflammatory diseases, especially, acute lung injury and pulmonary fibrosis. To address this question, we used mutant mice, i.e. PAFR transgenic mice, PAFR gene-disrupted mice and cPLA2 gene-disrupted mice. We have shown that PAF and eicosanoids, downstream mediators of cPLA2, may be involved in the pathogenesis of ARDS and IPF, which are important diseases in the elderly. Although there exist extreme differences in clinical features between ARDS and IPF, both diseases are fatal disorders for which no useful drugs are currently available. On the basis of recent reports using mutant mice, cPLA2 might be a potential target to intervene in the development of pulmonary fibrosis and acute lung injury in the elderly. [source] Long-term modulation of glucose utilization by IL-1, and TNF-, in astrocytes: Na+ pump activity as a potential target via distinct signaling mechanismsGLIA, Issue 1 2002Céline Véga Abstract Interleukin-1, (IL-1,) and tumor necrosis factor-, (TNF-,) markedly stimulate glucose utilization in primary cultures of mouse cortical astrocytes. The mechanism that gives rise to this effect, which takes place several hours after application of cytokine, has remained unclear. Experiments were conducted to identify the major signaling cascades involved in the metabolic action of cytokine. First, the selective IL-1 receptor antagonist (IL-1ra) prevents the effect of IL-1, on glucose utilization in a concentration-dependent manner, whereas it has no effect on the action of TNF-,. Then, using inhibitors of three classical signaling cascades known to be activated by cytokines, it appears that the PI3 kinase is essential for the effect of both IL-1, and TNF-,, whereas the action of IL-1, also requires activation of the MAP kinase pathway. Participation of a phospholipase C-dependent pathway does not appear critical for both IL-1, and TNF-,. Inhibition of NO synthase by L-NAME did not prevent the metabolic response to both IL-1, and TNF-,, indicating that nitric oxide is probably not involved. In contrast, the Na+/K+ ATPase inhibitor ouabain prevents the IL-1,- and TNF-,-stimulated 2-deoxyglucose (2DG) uptake. When treatment of astrocytes with a cytokine was followed 24 h later by an acute application of glutamate, a synergistic enhancement in glucose utilization was observed. This effect was greatly reduced by ouabain. These data suggest that Na+ pump activity is a common target for both the long-term metabolic action of cytokines promoted by the activation of distinct signaling pathways and the enhanced metabolic response to glutamate. GLIA 39:10,18, 2002. © 2002 Wiley-Liss, Inc. [source] Genotype-dependent sensitivity of hepatitis C virus to inhibitors of the p7 ion channel,HEPATOLOGY, Issue 6 2008Stephen Griffin The hepatitis C virus (HCV) p7 protein plays a critical role during particle formation in cell culture and is required for virus replication in chimpanzees. The discovery that it displayed cation channel activity in vitro led to its classification within the "viroporin" family of virus-coded ion channel proteins, which includes the influenza A virus (IAV) M2 protein. Like M2, p7 was proposed as a potential target for much needed new HCV therapies, and this was supported by our finding that the M2 inhibitor, amantadine, blocked its activity in vitro. Since then, further compounds have been shown to inhibit p7 function but the relationship between inhibitory effects in vitro and efficacy against infectious virus is controversial. Here, we have sought to validate multiple p7 inhibitor compounds using a parallel approach combining the HCV infectious culture system and a rapid throughput in vitro assay for p7 function. We identify a genotype-dependent and subtype-dependent sensitivity of HCV to p7 inhibitors, in which results in cell culture largely mirror the sensitivity of recombinant protein in vitro; thus building separate sensitivity profiles for different p7 sequences. Inhibition of virus entry also occurred, suggesting that p7 may be a virion component. Second site effects on both cellular and viral processes were identified for several compounds in addition to their efficacy against p7 in vitro. Nevertheless, for some compounds antiviral effects were specific to a block of ion channel function. Conclusion: These data validate p7 inhibitors as prototype therapies for chronic HCV disease. (HEPATOLOGY 2008;48:1779-1790.) [source] Correlation of hypoxic signalling to histological grade and outcome in cartilage tumoursHISTOPATHOLOGY, Issue 5 2010Stephane Boeuf Boeuf S, Bovée J V M G, Lehner B, Hogendoorn P C W & Richter W (2010) Histopathology56, 641,651 Correlation of hypoxic signalling to histological grade and outcome in cartilage tumours Aims:, The molecular mechanisms underlying the progression of central chondrosarcoma are so far poorly understood. The aim of this study was to identify genes involved in the progression of these tumours by comparison of gene expression and correlation of expression profiles to histological grade and clinical outcome. Methods and results:, Array-based gene expression profiling of 19 chondrosarcoma samples was performed. Beside differences in the expression of cartilage matrix molecules, high-grade chondrosarcoma showed enhanced expression of the matrix metalloproteinase MMP-2 and of the hypoxia-inducible molecule galectin 1. Immunohistochemical analysis of galectin 1 and of further hypoxia-associated proteins was performed on 68 central and peripheral tumour samples. Hypoxia-inducible factor 1, (HIF-1,) activation was significantly elevated in high-grade central chondrosarcoma. A negative correlation of carbonic anhydrase IX expression to metastasis-free survival was independent of histological grade. Conclusions:, The expression patterns identified in this study point towards a substantial role for angiogenic and hypoxic signalling in chondrosarcoma progression. The constitutive activation of the transcription factor HIF-1, in high-grade chondrosarcoma could play a central role in the regulation of cell metabolism and vascularization in these tumours and may, for this reason, represent a potential target for chondrosarcoma therapy. [source] Contribution of TNFSF15 gene variants to Crohn's disease susceptibility confirmed in UK populationINFLAMMATORY BOWEL DISEASES, Issue 6 2008Mark Tremelling MRCP Abstract Background: Identification of Crohn's disease (CD)-associated genetic variants is key to understanding pathogenic pathways underlying disease susceptibility. Recent reports of an association between TNFSF15 variants and CD have been modestly replicated in European populations, suggesting heterogeneity at this locus with stronger CD association in Japanese than European populations. Methods: We investigated the association between variants in TNFSF15 and CD in 756 CD patients and 636 controls. Disease subphenotype associations were also investigated. Results:TNFSF15 single nucleotide polymorphism (SNP) variants were associated with CD in our panel with peak odds ratio (OR) 1.2 (95% confidence interval [CI] 1.01,1.41) P = 0.033. The presence of a risk haplotype was replicated for the first time in a European population (frequency 67% in cases and 61% in controls) OR = 1.44 (95% CI 1.23,1.68) P = 0.00012. This result mirrors the UK panel in the index study (Yamazaki et al [2005] Hum Mol Genet 14:3499,3506) but is less significant than that reported in Japanese populations. There was no evidence of association with any individual CD subphenotype. Conclusions: Variants in TNFSF15 contribute to overall CD susceptibility in European populations, although to a lesser extent than that seen in the Japanese. Further studies to define the precise disease-causing variants as well as targeted functional studies are now required in human CD as TNFSF15 is a potential target for biological therapies. (Inflamm Bowel Dis 2008) [source] Kisspeptin/GPR54 system as potential target for endocrine disruption of reproductive development and functionINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 2 2010M. Tena-Sempere Summary Kisspeptins, the products of Kiss1 gene acting via G protein-coupled receptor 54 (also termed Kiss1R), have recently emerged as essential gatekeepers of puberty onset and fertility. Compelling evidence has now documented that expression and function of hypothalamic Kiss1 system is sensitive not only to the activational effects but also to the organizing actions of sex steroids during critical stages of development. Thus, studies in rodents have demonstrated that early exposures to androgens and oestrogens are crucial for proper sexual differentiation of the patterns of Kiss1 mRNA expression, whereas the actions of oestrogen along puberty are essential for the rise of hypothalamic kisspeptins during this period. This physiological substrate provides the basis for potential endocrine disruption of reproductive maturation and function by xeno-steroids acting on the kisspeptin system. Indeed, inappropriate exposures to synthetic oestrogenic compounds during early critical periods in rodents persistently decreased hypothalamic Kiss1 mRNA levels and kisspeptin fibre density in discrete hypothalamic nuclei, along with altered gonadotropin secretion and/or gonadotropin-releasing hormone neuronal activation. The functional relevance of this phenomenon is stressed by the fact that exogenous kisspeptin was able to rescue defective gonadotropin secretion in oestrogenized animals. Furthermore, early exposures to the environmentally-relevant oestrogen, bisphenol-A, altered the hypothalamic expression of Kiss1/kisspeptin in rats and mice. Likewise, maternal exposure to a complex cocktail of endocrine disruptors has been recently shown to disturb foetal hypothalamic Kiss1 mRNA expression in sheep. As a whole, these data document the sensitivity of Kiss1 system to changes in sex steroid milieu during critical periods of sexual maturation, and strongly suggest that alterations of endogenous kisspeptin tone induced by inappropriate (early) exposures to environmental compounds with sex steroid activity might be mechanistically relevant for disruption of puberty onset and gonadotropin secretion later in life. The potential interaction of xeno-hormones with other environmental modulators (e.g., nutritional state) of the Kiss1 system warrants further investigation. [source] Distinct expression patterns of the immunogenic differentiation antigen NY-BR-1 in normal breast, testis and their malignant counterpartsINTERNATIONAL JOURNAL OF CANCER, Issue 7 2008Jean-Philippe Theurillat Abstract NY-BR-1 is a differentiation antigen and a potential target for cancer immunotherapy. Its mRNA expression is restricted to breast, testis, prostate and breast cancer by RT-PCR. In this study, we correlated NY-BR-1 protein and mRNA expression on tissue microarrays of mammary, prostatic and testicular malignancies using immunohistochemisty and in situ hybridization with probes for exon 4,7 and 30,33. NY-BR-1 mRNA was confined to primary spermatocytes, suggesting a role in spermatogenesis. Exon 4,7 and 30,33 were equally expressed this cell type. However, NY-BR-1 was absent in all germ cell tumours analyzed (n = 475) and present in one of 56 (2%) prostate carcinomas. In breast, NY-BR-1 mRNA expression was detected in 307 of 442 (70%) primary carcinomas, with strong correlation to its protein expression (p < 0.0001). mRNA expression was significantly stronger and more frequently detected by the exon 30,33 probe than by the exon 4,7 probe (70% vs. 35%, p < 0.0001), indicating the presence of alternative splice variants that lack 5-prime sequences. A similar restricted mRNA pattern was also observed in the normal breast epithelium. NY-BR-1 protein and mRNA correlated significantly with estrogen receptor , (ER,) protein expression (p < 0.0001), with stronger association to NY-BR-1 mRNA than protein (odds ratio 7.7 compared to 4.6). We identified 4 estrogen response elements (ERE)-like sequences nearby the promoter region, suggesting that NY-BR-1 transcription might be controlled by ER,. Accordingly, analysis of matching pairs of primary tumors with their recurrences showed a marked decrease of NY-BR-1 expression in recurrences after tamoxifen treatment (p < 0.0001). © 2007 Wiley-Liss, Inc. [source] Stromelysin-3 expression is an early event in human oral tumorigenesisINTERNATIONAL JOURNAL OF CANCER, Issue 2 2003Shilpi Soni Abstract Stromelysin-3 (ST3/MMP11) is associated with human tumour progression. To determine the clinical significance of ST3 in oral tumorigenesis, its expression was analysed in different stages of tobacco-associated oral cancer. Immunohistochemical analysis of ST3 expression in 79 oral precancerous lesions, 177 SCCs and 35 histologically normal oral tissues was carried out and corroborated by immunoblotting and RT-PCR. ST3/MMP11 protein expression was observed in 45/79 (57%) precancerous lesions [28/48 (58%) with hyperplasia and 17/31 (55%) with dysplasia] and in 123/177 (70%) oral SCCs. In precancerous lesions, ST3 expression was higher compared to normal oral tissues (p = 0.000) and associated with MVD (p = 0.05), a marker for angiogenesis. ST3 was also expressed in cells cultured from precancerous and cancerous lesions that had undergone epithelial-to-mesenchymal transition. In oral cancer patients, ST3 positivity was associated with lymph node involvement (p = 0.025) and increased intratumoral MVD (p = 0.009). Ninety-eight oral SCC patients were followed up for a period of 94 months (median 22.5 months). Kaplan-Meier survival analysis showed that ST3 expression was not a significant prognostic indicator. ST3 expression in oral hyperplastic and dysplastic lesions suggests its association with progression of phenotypic alterations acquired early during the malignant transformation pathway of oral epithelium and implicates it not only in angiogenesis and invasion but also in tumorigenesis. Thus, ST3 may serve as a potential target for developing molecular therapeutics for early intervention in oral tumorigenesis. © 2003 Wiley-Liss, Inc. [source] What is a role of haeme oxygenase-1 in psoriasis?INTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 2 2007Current concepts of pathogenesis Summary The skin is constantly exposed to endogenous and environmental pro-oxidant agents, which lead to harmful generation of reactive oxygen species (ROS). Healthy skin, being a potential target for oxidative stress, is equipped with a large number of defence mechanisms including antioxidant systems. This protection can be corrupted by an imbalance between ROS and antioxidants with pathological level of oxidants prevailing. There is a great body of evidence indicating that some inflammatory skin diseases, such as psoriasis, are mediated by oxidative stress. Keratinocytes of normal skin, the primary target for pro-oxidant agents, show strong expression of ROS-detoxifying enzymes. In addition, normal keratinocytes express haeme oxygenase (HO), an enzyme which might be involved in the protection of cells against oxidative stress. HO (inducible HO-1, constitutive HO-2 and HO-3) is the rate-limiting enzyme in haeme catabolism, which leads to the generation of biliverdin, iron, and carbon monoxide. HO-1 is a stress-responsive protein whose expression is induced by various oxidative agents. HO-1 is known for its cytoprotective, antioxidant and anti-inflammatory properties. Interestingly, a strong overexpression of HO-1 was observed in psoriatic skin. However, the role of HO-1 in psoriasis remains unclear. In this review, we will discuss some current concepts concerning pathogenesis of psoriasis and the contribution of HO-1 in skin inflammation to show the relationships between HO-1, ROS and cytokine network in psoriatic skin. We will try to answer a question whether enhanced HO-1 expression in keratinocytes results in beneficial or detrimental effect on the development and severity of psoriatic lesions. [source] Skeletal muscle glucose uptake during exercise: A focus on reactive oxygen species and nitric oxide signalingIUBMB LIFE, Issue 5 2009Troy L. Merry Abstract Like insulin, muscle contraction (in vitro or in situ) and exercise increase glucose uptake into skeletal muscle. However, the contraction/exercise pathway of glucose uptake in skeletal muscle is an independent pathway to that of insulin. Indeed, skeletal muscle glucose uptake is normal during exercise in those who suffer from insulin resistance and diabetes. Thus, the pathway of contraction-mediated glucose uptake into skeletal muscle provides an attractive potential target for pharmaceutical treatment and prevention of such conditions, especially as skeletal muscle is the major site of impaired glucose disposal in insulin resistance. The mechanisms regulating skeletal muscle glucose uptake during contraction have not been fully elucidated. Potential regulators include Ca2+ (via CaMK's and/or CaMKK), AMPK, ROS, and NO signaling, with some redundancy likely to be evident within the system. In this review, we attempt to briefly synthesize current evidence regarding the potential mechanisms involved in regulating skeletal muscle glucose uptake during contraction, focusing on ROS and NO signaling. While reading this review, it will become clear that this is an evolving field of research and that much more work is required to elucidate the mechanism(s) regulating skeletal muscle glucose uptake during contraction. © 2009 IUBMB IUBMB Life 61(5): 479,484, 2009 [source] siRNA-targeted COL8A1 inhibits proliferation, reduces invasion and enhances sensitivity to D -limonence treatment in hepatocarcinoma cellsIUBMB LIFE, Issue 1 2009Yongfu Zhao Abstract The COL8A1 (collagen type VIII, alpha-1) gene, which encodes the alpha 1 chain of collagen, type VIII, may modulate migration, proliferation and adherence of various cells. Only very sparse information exists on COL8A1 expression in hepatocarcinoma. To investigate the possible role of COL8A1 in the mouse hepatocarcinoma cell line Hca-F with highly metastatic potential in the lymph nodes, we used an RNA interference (RNAi) approach to silence COL8A1 expression. The results showed that a small interfering RNA (siRNA) targeted against COL8A1 significantly impeded Hca-F cells proliferation and colony formation in soft agar. This reduction of COL8A1 expression also led to the decreased invasion of Hca-F cells dramatically in vitro. Furthermore, the downregulation of COL8A1 expression also sensitized cells to the action of D -limonene. These data together provide insights into the function of COL8A1 and suggest that COL8A1 might represent a new potential target for gene therapy in hepatocarcinoma. © 2008 IUBMB IUBMB Life, 61(1): 74,79, 2009 [source] Hepatotoxic effect of cyclosporin A in the mitochondrial respiratory chainJOURNAL OF APPLIED TOXICOLOGY, Issue 4 2007Lilia Cristina De la Cruz Rodríguez Abstract Cyclosporin A (CyA), a potent immunosuppressant, was used to determine the hepatotoxic effect in long-term treatments. Male Wistar rats were used in these experiments. They were given CyA chronically at doses used in patients for 120 days, and at doses of 5, 10, 15 and 20 mg kg,1 day,1. These doses amount to CyA values in blood of 200 ± 24, 314 ± 40, 445 ± 33 and 598 ± 53 ng ml,1, respectively. A significant increase in glutamate dehydrogenase (GLDH) was found in the groups treated with 15 and 20 mg kg,1 day,1, which would point to mitochondria as the potential target of the toxic action of CyA. The mitochondrial respiratory chain of rat livers was studied in enzyme complexes I and II. Enzyme complex I was determined by spectrophotometry at 340 nm using NADH oxidase with the respirable substrate 10 mm NADH; enzyme complex II was determined by monitoring succinate dehydrogenase by oxymetry using the respirable substrate 10 mm succinate. The results show the inhibition of NADH oxidase in the groups treated with 10, 15 and 20 mg kg,1 day,1, an effect dependent both on time and on CyA concentration. Enzyme complex II showed a decrease in oxygen consumption. These findings were confirmed by histological studies (hematoxylin-eosin technique). Conclusions: Long-term treatment with CyA at doses of 15 and 20 mg kg,1 day,1, amounting to concentrations in blood of 445 ± 33 and 598 ± 53 ng ml,1, causes alterations in the mitochondria, revealed by the increase in serum GLDH and by the functional alteration of enzyme complexes I and II of the mitochondrial respiratory chain. Copyright © 2007 John Wiley & Sons, Ltd. [source] Evaluation of the antimicrobial activity of ebselen: Role of the yeast plasma membrane H+ -ATPaseJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 5 2007Grace Chan Abstract Ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one) is a selenium-containing antioxidant demonstrating anti-inflammatory and cytoprotective properties in mammalian cells and cytotoxicity in lower organisms. The mechanism underlying the antimicrobial activity of ebselen remains unclear. It has recently been proposed that, in lower organisms like yeast, the plasma membrane H+ -ATPase (Pma1p) could serve as a potential target for this synthetic organoselenium compound. Using yeast and bacteria, the present study found ebselen to inhibit microbial growth in a concentration- and time-dependent manner, and yeast and Gram-positive bacteria to be more sensitive to this action (IC50 , 2,5 ,M) than Gram-negative bacteria (IC50 < 80 ,M). Washout experiments and scanning electron microscopic analysis revealed ebselen to possess fungicidal activity. In addition, ebselen was found to inhibit medium acidification by PMA1 -proficient haploid yeast in a concentration-dependent manner. Additional studies comparing PMA1 (+/,) and PMA1 (+/+) diploid yeast cells revealed the mutant to be more sensitive to treatment with ebselen than the wild type. Ebselen also inhibited the ATPase activity of Pma1p from S. cerevisae in a concentration-dependent manner. The interaction of ebselen with the sulfhydryl-containing compounds L -cysteine and reduced glutathione resulted in the complete and partial prevention, respectively, of the inhibition of Pma1p ATPase activity by ebselen. Taken together, these results suggest that the fungicidal action of ebselen is due, at least in part, to interference with both the proton-translocating function and the ATPase activity of the plasma membrane H+ -ATPase. © 2007 Wiley Periodicals, Inc. J Biochem Mol Toxicol 21:252,264, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20189 [source] ADAM8 expression is associated with increased invasiveness and reduced patient survival in pancreatic cancerJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 5 2007N. Valkovskaya Abstract ADAM8 belongs to a family of transmembrane proteins implicated in cell,cell interactions, proteolysis of membrane proteins, and various aspects of carcinogenesis. In the present study, we aimed to evaluate the expression and function of ADAM8 in pancreatic cancer. ADAM8 mRNA levels were analysed by quantitative RT-PCR and correlated to patient survival. Immunohistochemistry was performed to localize ADAM8 in pancreatic tis-sues. Silencing of ADAM8 expression was carried out by transfection with specific siRNA oligonucleotides. Cell growth and invasion assays were used to assess the functional consequences of ADAM8 silencing. SELDI-TOF-MS was performed to detect the proteolytic activity of ADAM8 in pancreatic cancer cells. ADAM8 mRNA was significantly overexpressed in pancreatic ductal adenocarcinoma (PDAC) compared with normal pancreatic tissues (5.3-fold increase; P= 0.0008), and high ADAM8 mRNA and protein expression levels correlated with reduced survival time of PDAC patients (P= 0.048 and P= 0.065, respectively). Silencing of ADAM8 expression did not significantly influence pancreatic cancer cell growth but suppressed invasiveness. In addition, decreased proteolytic activity was measured in cell culture supernatants following silencing of ADAM8. In conclusion, ADAM8 is overexpressed in PDAC, influences cancer cell invasiveness and correlates with reduced survival, suggesting that ADAM8 might be a potential target in pancreatic cancer therapy. [source] Serotonin receptors antagonistically modulate Caenorhabditis elegans longevityAGING CELL, Issue 4 2007Hana Murakami Summary The neurotransmitter serotonin has been implicated in affecting the variation of longevity in natural Drosophila populations and age-related diseases in mammals. Based on these observations, it has been predicted that serotonin signal, perhaps at levels of serotonin biosynthesis, may control lifespan. Here, we investigated a variety of mutations in serotonin-signal genes, including serotonin biosynthesis genes, a serotonin transporter gene, and serotonin receptor genes. Despite this prediction, mutations in the serotonin biosynthesis genes had little or modest effects on lifespan, while the mod-5 mutation with increased availability of serotonin caused a modest life-shortening effect. In contrast, a deletion mutation of the ser-1 serotonin receptor gene increased longevity by up to 46%, likely through the insulin/insulin-like growth factor 1 pathway. This result suggests an interaction between the serotonin pathway and the insulin/insulin-like growth factor 1 pathway. A deletion mutation of another serotonin receptor gene, ser-4, shortened early to mid lifespan. The results suggest that serotonin signal antagonistically modulates longevity through different serotonin receptors. This study may indicate serotonin receptors as a potential target for antigeric interventions. [source] Inhibition of CCAAT/enhancer binding protein , expression by chrysin in microglial cells results in anti-inflammatory and neuroprotective effectsJOURNAL OF NEUROCHEMISTRY, Issue 2 2010Núria Gresa-Arribas J. Neurochem. (2010) 115, 526,536. Abstract The control of neuroinflammation is a potential target to be considered in the treatment of neurodegenerative diseases. It is therefore important to find anti-inflammatory drugs and study new targets that inhibit neuroinflammation. We designed an experimental model of neuroinflammation in vitro to study the anti-inflammatory and neuroprotective effects of the flavonoid chrysin and the involvement of nuclear factor-,B p65 and CCAAT/enhancer binding proteins (C/EBPs) , and , transcription factors in its mechanism of action. We used primary cultures of mouse embryonic cortical neurons and cultures of BV2 (murine microglial cell line) or mouse primary microglia. We induced neuronal death in neuronal-BV2/microglial co-cultures using lipopolysaccharide of Escherichia coli and interferon-,. Chrysin pre-treatment inhibited nitric oxide and tumor necrosis factor-, production, as well as inducible nitric oxide synthase expression in lipopolysaccharide E. coli and interferon-,-treated microglial cells, but did not affect cyclooxygenase-2 expression. Chrysin pre-treatment also protected neurons against the neurotoxicity induced by reactive microglial cells. These effects were associated to a decrease in C/EBP, protein level, mRNA expression, and DNA-binding activity, with no effect on C/EBP, and p65 nuclear protein levels or DNA-binding activity, pointing out C/EBP, as a possible mediator of chrysin effects. Consequently, C/EBP, is a possible target to act against neuroinflammation in neurodegenerative processes. [source] Activated JNK brings about accelerated apoptosis of Bcl-2-overexpressing C6 glioma cells on treatment with tamoxifenJOURNAL OF NEUROCHEMISTRY, Issue 1 2005Madhavi S. Moodbidri Abstract Tamoxifen causes apoptosis of malignant glial cells at a concentration that does not kill normal astrocytes. C6 glioma cells were stably transfected with a vector expressing Bcl-2 under the control of metallothionin promoter. Low leaky Bcl-2 expression offered complete protection against tamoxifen-induced apoptosis. High Bcl-2 levels, on the other hand, accelerated the apoptosis, with Bcl-2-overexpressing clones dying within 48 h of tamoxifen treatment as compared to 6 days for parental C6 cells. Overexpressed Bcl-2 is localized primarily in mitochondria and to a much lower extent in endoplasmic reticulum (ER). Only a minor fraction of the overexpressed Bcl-2 gets phosphorylated in tamoxifen-treated cells and the phosphorylation does not affect its binding to Bax. Tamoxifen treatment of Bcl-2-overexpressing clones was found to result in activation of c-Jun N-terminal kinase (JNK) and p38 kinase. Inhibition of JNK but not p38 kinase completely abrogated the accelerated apoptosis. Constitutively expressed endogenous c-Jun was found to be phosphorylated, resulting in increased activator protein 1 (AP-1) DNA-binding activity. Expression of Fas ligand (FasL), an AP-1 transcriptional target, increased during accelerated cell death. This presumably brought about activation of caspase 8, as inhibition of caspase 8 blocked the apoptosis. The JNK/c-Jun/AP-1/FasL pathway could be considered as a potential target for the therapy of gliomas. [source] | ||||||||||||||||||||||||||||||||||||||||